Thwarting the Avalon's Effort
After they arrived at the end of the tunnel, Samiel realized that they were already near the targetted location, judging by the sheer number of protective Wards that were all around them. From the look of an amateur, one could say that the people setting up the defenses here were pretty paranoid... but...
Fortunately, though, all of the defensive and even offensive wards were deactivated because they would be activated only during times of danger and that meant an imminent attack. This was, in fact, a foolish decision because if the wards were already placed, then not activating them at all times was a pretty idiotic thing to do, as they would be useless.
Normally speaking, when the wards were deactivated, then their subsequent activation would require at least several seconds, sometimes even half a minute, which was a too big window of opportunity for the potential attackers. If someone was experienced enough, he could have destroyed the wards countless times over.